Guard for slate-trimming machines.



D. C. SHERMAN.

GUARD FOR SLATE TRIMMING MACHINES. APPLICATION FILED SEPT. 9. 1916.

1,235,068. Patented July 31, 1917.

2 SHEETS-SHEET I. 5 7 9 grrucnfo'z,

D. C. SHERMAN. GUARD FOR SLATE TRIMMING MACHINES. APPLICATION FILED SEPT. 9. 1916.

1,235,068. Patefited July31, 1917.

2 SHEETS-SHEET 2- L "*I mwszixltf stationary knife.

-ntarsrisrarns harass GUARD FOR SLATE-TRIMMING MEUHINES.

Specification of Letters Patent.

Eatentierl July 31, 131 Z.

Application filed September 9, 1916. Serial No. 119,203.

To all whom it may concern Be it known that I, Dav n CLARENCE SHERMAN, a citizen of the United States, residing at Poultney, in the county of Butland, State of Vermont, have invented certain new and useful Improvements in Guards for Slate-Trimming Machines, of which the following is a description reference being had to the accompanying drawings, forming a part thereof.

My invention relates to guards for slate trimming or other machines in which a rotary or otherwise movable knife is used to outer break the material operated on and is designed to protect the operator of such a machine from injury from the movable knife.

In slate trimming machines of the type for which my invention is particularly in tended the slate to be trimmed rests upon a stationary knife with which a rotary or swinging knife cooperates to cut or break the slate along the line of the edge of the In order to effect this cutting or breaking of the slate the rotary or swinging knife must not only be of considerable we'ght but must be brought down upon the slate with very considerable force. The slate is held in position by the hands of the operator and the operation of the movable knife is usually controlled by or actuated by a treadle. There is always more or less danger that the operators foot may slip on the trtndle and in putting out his hand to catch himself the hand may get between. the kni es and be injured.

It is the object of my invention to proride a simple and inexpensive and at the same time effective guard by which without interfering with the operation of the ma chine it be made impossible for the operator to accidentally get his hand hetwecn'the knives.

With this and other objects hereinafter explained in view my invention consists in the construction and combination of elements hereinafter described and particularly pointed out in the claims.

Referring to the drawings. Figure a front elevation of a slate trimming ma chine provided with'the guard of my invention.

Fig. 2 is an end View taken from the right of Fig. 1.

Fig. 8 is a vertical sectional view on the knife 9. The movable knife 10 is carried by arms 11 and 12 on shaft 6. The movable knife is so constructed that its cutting edge is not parallel with the axis of shaft 6 but is so curved that its end. which is at the right in Fig. 1 comes first into line with the edge of the .ationary knife.

On one end of shaft 6 is a fly wheel 13 having crank pin 14 connected by pitman 15 with treadle 16.

A gage bar 17 is pivoted at 18 to a fixed plate 19 carried. by the front plate 2 the gage bar being adjustable on its pivot 18 by means of slot 20 and bolt 21. The gage bar 17 is provided with notched gage 22 which is adjustable on the gage bar by means of slots 23 and bolts 24.

In the operation of the machine the slate to be trimmed is laid with its front end on plate 2 is bolted the stationary" the stationary knife and its left hand edge against the gage bar. The treadle is then pressed to rotate the shaft bringing the rotary knife down on the end of the slate shearing oil the portion projecting beyond the edge of the stationary knife. lhc slate having one edge thus trimmed is then turned to bring the trinmied edge against chine.

started? cannot be stopped quickly and will out or severely bruise the hand if it is in the path of the rotary knife. In order to make it impossible forsuch an accident to happen I provide the guard which is the This comprises of theframe of the machine hy bolts 28,

the support 27 being preferably twisted lietween its ends for convenience in securing its ends respectively to the cnd curved bar 21 and to theside of the frame of the ma- The intermediate curve ft bar is secured at its rear end to horizontal bar 24:. Secured to the under side of the curved bars 20, 21 and and to the horizontal bars 245 and 25 is a wire netting The curved bars 20, 21 and 22 are of such length that the front horizontal bar'23 is held a sufficient distance above the plane of the edge of the stationary knife to permit the slate to be trimmed to be inserted and the snpport 27 is so bent as not to prevent the insertion of the full width of the machine or even wider.

The curved and horizontal bars are preferahl formed of llatstrips of steel or other metal and the netting is formed of Wire sutliciently-strong to resist any pressure of the hand of the operator. The curve on which the curved bars 20 and 21 and are formed is approximately an arc of a circle of which the axis of the shaft 6 is the center.

A suitable apron 30 extends from the top front 2 downward and rearward so that the chips from the trimming operation are discharged to the rear.

The guard not only prevents the hands of 3011198 of thisipatent may be obtained for five cents each, by addressing the Commissioner the operator from getting between the knives but also prevents chips from. flying as the slate is trimmed.

lVhile the guard has been described as applied to a slate trimming macl'iine, it is obvious that it may he applied to any machine in which a rotary knife is arranged to cut or trim sheets or other material in cotipera-- tion with a stationary knife,

Having thus describedmy invention What I claim is:

1. In a cutting machine having a stationary knife and a rotary knife, arranged tionary knife and a rotary knife arranged to cooperate with the stationary knife. guard colnprislng curved bars seem-ed at their rear-ends to the frame of the machine and extending over the knives. a horizontal bar secured to the front ends of the curved bars above the plane of the stationary knife, and a netting carried by the curved arms extending over the rotary knife, and supports for the front ends of the curved hars.

3. In av cutting machine having a sta tionarv knife and a rotary knife arranged to cooperate with the stationary knife, a guard comprising curved bars secured at their rear ends to the frame of the machine and extending over the knives, a horizontal bar secured to the front ends of the curved bars alcove the plane of the stationary knife,

of Eatents,

Washington, 33. G. 

